The overall objective of the proposed research is to determine the mechanisms by which ovarian hormones regulate amounts and activities of specific uterine enzymes. More specifically, we plan to determine the mechanisms by which progesterone and estradiol control rates of enzyme synthesis and degradation in the endometrium and myometrium of the pseudopregnant rat uterus during decidualization. The contribution of transcriptional and translational control mechanisms to the synergism of progesterone and estradiol in the control of endometrial enzyme levels will be determined. Results of these experiments will be extended and refined with the development of in vitro organ or cell culture techniques for the uterine endometrium. An understanding of mechanisms of control of protein synthesis in the endometrium and myometrium of the uterus should contribute to our understanding of the processes of implantation and early placental development.